Substrate water status and evapotranspiration irrigation scheduling in heterogenous container nursery crops

In Europe, one of the major production centres for hardy ornamental nursery stocks is located around the town of Pistoia in Tuscany, Italy. The map refers to 2004, when nearly 1500 nurseries were in operation on about 4600 ha. Since then, nursery industry has expanded steadily with an increasing application of container cultivation, which currently covers around 1000 ha. Annual water consumption of the whole nursery industry is estimated to be around 12 million m3, which approximates the urban water consumption of Pistoia. Due to over-irrigation, huge quantities of water are being used in nurseries, in particular for container crops that consume 75-80% of the total water demand of HONS industry. Inaccurate scheduling is the main cause of excessive irrigation. Growers generally estimate crop water needs based on personal experience and use simple timers for automated irrigation. The asterisk on the map indicates the Experimental Station for Nursery Crops (Ce.Spe.Vi.), where the irrigation study was conducted. Compared with traditional timer, substrate water status and evapotranspiration irrigation scheduling reduced considerably both water use (−21% to −40%) and nutrient emission (−39% to −74%) in heterogeneous container nursery crops, with no significant effects on plant growth and quality.